| The purpose of this work was to study the dry sliding wear properties of aluminum matrix composites A356Al-SiC, 6061Al-AlTo study the plastic deformation and damage accumulation below the contact surfaces, new metallographic techniques have been developed and used to determine the magnitude of the shear strains and the microhardness gradients in near surface regions. Under dry sliding wear conditions, both the magnitude of plastic strains and the depth of heavily deformed zones increased with sliding distance and applied load. The flow stress and the plastic strains in the deformed zones are shown to obey a Voce type work hardening law. A model based on the hypothesis that delamination cracks leading to the generation of wear debris are formed by the coalescence of voids at a critical depth below the worn surfaces has been proposed. It is shown that the critical depth for maximum rate of damage accumulation is determined by a competition between the plastic strain which enhances void growth and the hydrostatic pressure which suppresses it. |
